1. Technical Field
The present invention relates to the prevention or treatment of diabetes-related diseases using C-peptide. More particularly, the present invention relates to a method for prevention or treatment of diabetic vascular leakage-induced diseases using C-peptide, a method for prevention or treatment of diabetic retinopathy, using C-peptide, and a composition for use in the prevention or treatment of the diseases, comprising C-peptide.
2. Description of the Related Art
As well known to those skilled in the art, Diabetes is a group of metabolic diseases with multiple etiologies, characterized by chronic hyperglycemia resulting from the absolute or functional deficiency of insulin activity. A high blood glucose level maintained for a long period of time causes a chronic metabolic disorder and causes damage to blood vessels, with the subsequent onset of various complications. These typically develop after 10 years of onset of diabetes because almost all organs of the body have been damaged. Particularly, abnormal vascular leakage is observed in diabetes patients, and diabetic vascular leakage induces various complications including diabetic retinopathy, diabetic neuropathy, diabetic nephropathy, diabetic vascular dysfunction, diabetic inflammation, etc.
These diabetic complications are relevant to the overexpression of VEGF (vascular endothelial growth factor). VEGF is likely to induce vascular leakage, and an increased level of VEGF in retinas of diabetes patients is known to induce angiogenesis and mascular edema. Further, a recent study has indicated that ROS generation and stress fiber formation interrupt VE-cadherin-based cell-cell adhesion at adherens junctions. Additionally, VE-cadherin is known as a requisite component to prevent the disassembly of blood vessel walls and to coordinate the passage of macromolecules through the endothelium.
Human C-peptide is a short peptide cleaved from proinsulin and is secreted in equimolar concentrations with insulin by pancreatic β-cells into the circulation. Deficiency of C-peptide, along with insulin, is a typical feature of type 1 diabetes mellitus as well as of the later stages of type 2 diabetes mellitus. Retinopathy is one of the major complications induced by diabetes and is the leading cause of blindness in adults. C-peptide is used for the diagnosis of diabetes, but there have been no reports on the application of C-peptide in the treatment of diabetic vascular leakage or secondhand diseases induced by diabetic vascular leakages.
From this background, the present inventors conducted intensive and thorough research into the treatment of diabetic vascular leakage, and found that C-peptide can be used for protecting VEGF-induced vascular leakage in diabetic retinopathy, leading to the present invention.